1. Field of the Invention
The present invention relates to an apparatus and a method for managing a heat source unit for an air conditioner.
2. Description of the Related Art
For example, the invention disclosed in Japanese Patent Laid-Open No. 26237/1997 is known as a remote central control method for a heat source unit for an air conditioner. According to this invention, a terminal unit is installed in an absorption chiller/heater. Then, by use of signals indicating physical quantities or operating states of respective portions of the absorption chiller/heater, abnormality is judged in an arithmetic control portion provided in the terminal unit. When abnormality is detected, a signal stored in the terminal unit is transmitted to a central monitoring unit. In an analyzing computer provided in the central monitoring unit, deeper analysis is carried out while an indication is made on a monitor portion provided in the central monitoring unit or a warning light is lit.
In addition, Japanese Patent Laid-Open No. 151416/1995 discloses an absorption chiller/heater in which only pollution of cooling water likely to persist for a long time can be judged accurately. FIG. 6 is a diagram showing the configuration of a typical double-effect type absorption refrigerator disclosed in Japanese Patent Laid-Open No. 151416/1995. In this double-effect type absorption refrigerator, an absorption refrigerator is used as a heat source unit for an air conditioner implemented conventionally. In FIG. 6, an upper body 601, a lower body 602, a high temperature regenerator 603, a high temperature heat exchanger 604, a low temperature heat exchanger 605, and so on, are connected with one another through pipe arrangement. The upper body 601 is constituted by a condenser 611 and a low temperature regenerator 612. The lower body 602 is constituted by an evaporator 621 and an absorber 622. The high temperature regenerator 603 includes a burner 631.
In the absorption refrigerator, cooling water is circulated between the refrigerator and an outdoor cooling tower. Therefore, dust or the like in the outside air is absorbed in the cooling water in the course of circulation. When the cooling water absorbing dust and the like passes through a heat exchange unit such as the absorber or the condenser, the heating surface thereof is polluted so that the heat exchange rate deteriorates. When the cooling water system of the absorption refrigerator is polluted, the efficiency of the refrigerator is reduced in proportion to the degree of the pollution. Then, the advance of this symptom may cause a serious failure such as abnormality in the high temperature regenerator or crystallization of absorbent. When such a failure occurs, operation cannot be kept on.
Therefore, in the invention disclosed in Japanese Patent Laid-Open No. 151416/1995, temperatures in a plurality of portions which may be affected by the pollution of the heating surface of cooling water pipe arrangement passing through the absorber and the condenser are detected by sensors. Then, evaluation data expressing the lowering of the heat transfer performance is made up on the basis of the outputs of the sensors. Time averages are calculated from the evaluation data and compared with their reference values. Thus, pollution of the cooling water is judged.
However, it is the pollution of the cooling water that can be judged in this invention. That is, the lowering of the performance of the absorption refrigerator as a heat source unit or the occurrence of abnormality in the absorption refrigerator due to other factors cannot be evaluated.
The present invention was developed in consideration of such actual situation of the related art. It is an object of the invention to provide a management apparatus and a management method in which time to inspect a heat source unit for an air conditioner can be forecast accurately before the performance of the heat source unit is lowered or abnormality occurs in the heat source unit.
It is another object of the invention to provide a management apparatus and a management method in which maintenance is carried out on the basis of the aforementioned accurate forecast so that the loss of a user using the heat source unit can be suppressed, and further the cost required for operating the heat source unit can be reduced.
To attain the foregoing objects, a first aspect of the invention provides an apparatus for managing at least one heat source unit for an air conditioner, including: means for analyzing cyclic operation condition of the heat source unit from operating data of the heat source unit, the cyclic operation condition having an operating cycle of operation, dilution and stop; means for averaging the cyclic operation condition for a predetermined period; means for storing the averaged data into a storage unit in time series; means for comparing the data stored in time series with analyzed data of current cyclic operation condition obtained by the analyzing means; means for detecting a variation, with time, in lowering of performance and/or degree of advance of abnormality in the heat source unit on and after start of use of the heat source unit, based on a comparison result produced by the comparing means; means for estimating degree of deterioration of the heat source unit on and after the start of use based on the variation with time; and means for determining maintenance time from a predetermined deterioration threshold value and the estimated degree of deterioration.
A second aspect of the present invention provides an apparatus for managing at least one heat source unit for an air conditioner, including: means for estimating temperatures of respective portions of the heat source unit during operation based on one of a temperature history during start-up of the heat source unit and a temperature history during stop of the heat source unit; means for averaging temperature in cyclic operation condition of the heat source unit for a predetermined period, the cyclic operation condition having an operating cycle of operation, dilution and stop; means for storing the averaged temperature data into a storage unit in time series; means for comparing the temperature data stored in time series with the temperature data of the respective portions estimated by the estimating means; means for detecting a variation, with time, in lowering of performance and/or degree of advance of abnormality in the heat source unit on and after start of use of the heat source unit, based on a comparison result produced by the comparing means; means for estimating degree of deterioration of the heat source unit on and after the start of use based on the variation with time; and means for determining maintenance time from a predetermined deterioration threshold value and the estimated degree of deterioration.
A third aspect of the present invention provides an apparatus for managing at least one heat source unit for an air conditioner, including a central monitoring unit connected to the heat source unit for the air conditioner through an information communication network and for carrying out remote central control upon the heat source unit for the air conditioner. The central monitoring unit includes a control unit for managing the heat source unit for the air conditioner. The control unit includes: means for analyzing cyclic operation condition of the heat source unit from operating data of the heat source unit transmitted through the information communication network, the cyclic operation condition having an operating cycle of operation, dilution and stop; means for averaging the cyclic operation condition for a predetermined period; means for storing the averaged data into a storage unit in time series; means for comparing the data stored in time series with analyzed data of current cyclic operation condition obtained by the analyzing means; means for detecting a variation, with time, in lowering of performance and/or degree of advance of abnormality in the heat source unit on and after start of use of the heat source unit, based on a comparison result between the stored data and the analyzed data; means for estimating degree of deterioration of the heat source unit on and after the start of use based on the variation with time; and means for determining maintenance time from a predetermined deterioration threshold value and the estimated degree of deterioration.
A fourth aspect of the present invention provides an apparatus for managing at lest one heat source unit for an air conditioner, including a central monitoring unit connected to the heat source unit for the air conditioner through an information communication network and for carrying out remote central control upon the heat source unit for the air conditioner. The central monitoring unit includes a control unit for managing the heat source unit for the air conditioner. The control unit includes: means for estimating temperatures of respective portions of the heat source unit during operation based on one of a temperature history during start-up of the heat source unit and a temperature history during stop of the heat source unit, the temperature histories being transmitted through the information communication network; means for averaging temperature in cyclic operation condition of the heat source unit for a predetermined period, the cyclic operation condition having an operating cycle of operation, dilution and stop; means for storing the averaged temperature data into a storage unit in time series; means for comparing the temperature data stored in time series with the temperature data of the respective portions estimated by the estimating means; means for detecting a variation, with time, in lowering of performance and/or degree of advance of abnormality in the heat source unit on and after start of use of the heat source unit, based on a comparison result between the stored temperature data and the estimated temperature data; means for estimating degree of deterioration of the heat source unit on and after the start of use based on the variation with time; and means for determining maintenance time from a predetermined deterioration threshold value and the estimated degree of deterioration.
According to a fifth aspect of the present invention, in the first to fourth aspects, a temperature history during operation of the heat source unit is compared with a pattern of a temperature history during occurrence of abnormality stored in the storage unit in advance, so as to conduct diagnosis on abnormal condition of the heat source unit.
According to a sixth aspect of the present invention, in the first to fourth aspects, there is further provided means for changing control logic concerning start and stop of the heat source unit in accordance with the degree of deterioration estimated by the means for estimating the degree of deterioration on and after the start of use based on the variation with time.
According to a seventh aspect of the present invention, in the first to fourth aspects, there is further provided means for changing control logic concerning start and stop of the heat source unit in accordance with the degree of deterioration estimated by the means for estimating the degree of deterioration on and after the start of use based on the variation with time. The means for changing the control logic selects control logic for stopping the heat source unit when the heat source unit is diagnosed as abnormal.
According to an eighth aspect of the present invention, in the first to fourth aspects, there is further provided means for changing control logic concerning start and stop of the heat source unit in accordance with the degree of deterioration estimated by the means for estimating the degree of deterioration on and after the start of use based on the variation with time. When the heat source unit is diagnosed as abnormal, the means for changing the control logic selects control logic to prevent abnormality from occurring in other portions due to the diagnosed abnormality of the heat source unit.
According to a ninth aspect of the present invention, in the first to fourth aspects, there are further provided: means for calculating real heat load on the air conditioner connected to the heat source unit, based on analytic data analyzed by the analyzing means; means for storing, into a storage unit, time-series data of the heat load on the air conditioner connected to the heat source unit; means for comparing the stored time-series data with current data, and judging whether a difference between the stored time-series data and the current data is permanent or not; and means for correcting and updating a pattern of the heat load to thereby estimate future heat load when the judging means concludes that the difference is permanent.
According to a tenth aspect of the present invention, in the first to fourth aspects, a plurality of heat source units are provided as the at least one heat source unit.
According to an eleventh aspect of the present invention, in the tenth aspect, there is further provided means for operating a heat source unit having a smaller degree of deterioration by priority based on the future heat load estimated by the means for estimating the heat load.
A twelfth aspect of the present invention provides a method for managing at least one heat source unit for an air conditioner, including the steps of: analyzing cyclic operation condition of the heat source unit from at least one piece of operating data of the heat source unit, the cyclic operation condition having an operating cycle of operation, dilution and stop; averaging the cyclic operation condition for a predetermined period; storing the averaged data into a storage unit in time series; comparing the data stored in time series with analyzed data of current cyclic operation condition obtained by the analyzing step; detecting a variation, with time, in lowering of performance and/or degree of advance of abnormality in the heat source unit on and after start of use of the heat source unit, based on a comparison result between the stored data and the analyzed data; estimating degree of deterioration of the heat source unit on and after the start of use based on the variation with time; and determining maintenance time from a predetermined deterioration threshold value and the estimated degree of deterioration.
A thirteenth aspect of the present invention provides a method for managing at least one heat source unit for an air conditioner, in which a central monitoring unit is connected to the heat source unit for the air conditioner through an information communication network and carries out remote central control upon the heat source unit for the air conditioner. The method includes the steps of: analyzing cyclic operation condition of the heat source unit from operating data of the heat source unit transmitted through the information communication network, the cyclic operation condition having an operating cycle of operation, dilution and stop; averaging the cyclic operation condition for a predetermined period; storing the averaged data into a storage unit in time series; comparing the data stored in time series with analyzed data of current cyclic operation condition obtained by the analyzing step; detecting a variation, with time, in lowering of performance and/or degree of advance of abnormality in the heat source unit on and after start of use of the heat source unit, based on a comparison result between the stored data and the analyzed data; estimating degree of deterioration of the heat source unit on and after the start of use based on the variation with time; and determining maintenance time from a predetermined deterioration threshold value and the estimated degree of deterioration.
According to a fourteenth aspect of the present invention, in the twelfth aspect or the thirteenth aspect, the cyclic operation condition is a temperature condition.
According to a fifteenth aspect of the present invention, in the twelfth aspect or the thirteenth aspect, a plurality of heat source units are provided as the at least one heat source unit.
Incidentally, in the embodiments which will be described later, the means for analyzing the cyclic operation condition corresponds to means for executing Step 204 in FIG. 2; the means for averaging the cyclic operation condition corresponds to means for executing Step 206 in FIG. 2; the storage unit corresponds to an equipment condition database 24; the means for storing the averaged data into the storage unit corresponds to means for executing Step 207 in FIG. 2; the means for detecting a variation with the passage of time corresponds to means for executing Step 208 in FIG. 2; and the estimating means and the determining means correspond to means for executing Step 209 and Step 210 in FIG. 2 respectively. The means for executing these steps corresponds to an equipment condition diagnosis portion 13.
In addition, the means for diagnosing the abnormal state of the heat source unit corresponds to means for executing Step 309 to Step 311 in FIG. 4. The means for executing these steps corresponds to the equipment condition diagnosis portion 13. In addition, means for changing the control logic about start and stop of the heat source unit corresponds to a control logic generation portion 14; the means for calculating the real heat load, the judging means and the means for estimating the future heat load correspond to a heat load calculation portion 61 respectively. The means for operating a heat source unit having a smaller degree of deterioration by priority corresponds to the control logic generation portion 14.
Further, the steps executed in the method correspond to the steps executed by the aforementioned respective means.